Mobile sales by retailers in the 2015 edition of the Internet Retailer Mobile 500, published today, will reach $83.78 billion in 2014, up 79.9% from $46.56 billion in 2013.

In 2014, $83.78 billion in mobile sales will account for 21.2% of an estimated $394.71 billion in total web sales by retailers in the Mobile 500, according to the 384-page guide, which ranks the top 500 retailers from across the globe by 2014 sales on smartphones and tablets.

The Mobile 500 does not include eBay Inc. because the online marketplace does not sell products on its own behalf and instead handles sales for merchants and individuals. But eBay does facilitate a massive amount of mobile commerce that must be factored into any mobile retail sales estimate. The Internet giant reported $20 billion in m-commerce sales in 2013, and Internet Retailer projects 70% growth in 2014 to $34 billion. Add up the Mobile 500 and eBay and the leaders in mobile commerce will hit $117.78 billion in 2014, up 77.0% from $66.56 billion in 2013.

The 2015 Mobile 500 ranks 366 U.S. retailers and 134 overseas retailers from China, the United Kingdom, Russia, Brazil, South Africa and 16 other countries. The 2015 edition also features 30 retailers new to the Mobile 500, including Sony Electronics Inc. (No. 66) and Nomorerack.com Inc. (No. 77). The guide includes 53 data points on each retailer, including financial indicators such as mobile sales and growth, operational metrics such as mobile unique visitors and mobile conversion rate, marketing data such as mobile marketing program features and mobile app features, and corporate information such as the mobile commerce director’s name and headquarters phone number.

The guide also includes analysis of each retailer’s mobile site performance and mobile search engine optimization performance. Internet Retailer worked with five firms for the 2015 Mobile 500: comScore Inc., Keynote, Mobidia Inc., Pure Oxygen Labs LLC and TheFind.

Data new to the Mobile 500 guide this year include, for each retailer, an itemization of mobile sales by smartphones versus tablets, a breakdown of mobile sales by web sites versus apps, mobile sales as a percentage of total web sales, mobile app sales as a percentage of mobile sales, and app engagement, which indicates how often regular app shoppers use an app.

For more information on the 2015 Mobile 500, including sample charts and sample retailer listings, or to order the guide, click here.

The 2015 Mobile 500 also reveals the vendors behind retailers’ mobile commerce smartphone sites, tablet sites and responsive design sites, and mobile apps. Branding Brand was the most-cited mobile commerce platform provider among the retailers in this year’s Mobile 500.

The guide also features a mobile commerce vendor directory, with 330 vendors listed by category.

59% of mobile sales among retailers in the 2015 Mobile 500 stem from tablets while 41% come from smartphones. However, many m-commerce experts predict that the rise of larger smartphones combined with ongoing mobile technology developments that make buying easier on smartphones—such as Apple opening up its biometric fingerprint scanner to developers to enable one-touch log-in and one-touch checkout—will tilt the mobile sales scales in favor of smartphones in the years to come.

Data in the Mobile 500 reveal various trends, but two are pronounced. First, the number of retailers in the 2015 Mobile 500 with responsive design web sites increased 164% compared with 2014. More than one-fifth of the leading retailers in m-commerce have gone responsive, and developers and other mobile experts predict that number could rise to half next year. Second, 42.4% of mobile sales in the 2015 edition stem from mobile apps while 57.6% come from web sites on smartphones and tablets. On average, a Mobile 500 retailer with apps gains about 30% of its mobile sales come from apps. Additionally, the number of apps offered by Mobile 500 retailers and the number of retailers offering apps have each increased significantly.

As a group, the top 10 retailers in mobile commerce, including the likes of Amazon.com Inc. (No. 1) and Apple Inc. (No. 2), will achieve 2014 mobile sales of $48.79 billion, up 83.0% from $26.66 billion in 2013.

Amazon.com changed its mobile commerce strategy last year. While the e-retailer continues to offer consumers a mobile-optimized site for smartphones, a desktop site enhanced for optimal shopping on tablets and a wide array of mobile apps, it has changed what a consumer can do and find on those sites and apps on smartphones and tablets.

“We want a customer to be able to have 100% of their relationship with Amazon on any device they choose,” says Paul Cousineau, director of mobile shopping at Amazon.com, which, with projected 2014 U.S. mobile sales of $16.8 billion, is No. 1 in the Mobile 500. “Mobile is a transformative technology. As our percentage of customers adopting mobile continues to grow, mobile can no longer be a limited subset of features or products. People do not put their phone down then go find a desktop to do something. They use their phone. And we think with clever use of functions and design, it is possible to give mobile customers 100%.”

Web and mobile measurement firm comScore says 29% of Amazon.com shoppers shop the e-retailer only on mobile devices, never accessing the retailer on a desktop or laptop PC. And the number of mobile-only shoppers is on the rise.

“Two years ago, we all envisioned a multi-device world where people would discover on the smartphone, browse on the tablet and land back on the desktop to buy,” says Scot Wingo, CEO of ChannelAdvisor Corp., which facilitates retailer sales through Amazon.com and other web marketplaces. “Well, multi-device shoppers are there, but they are transitioning to much more mobile. To some extent we were wrong about multi-device usage. The largest growth area in shopping and on the web is mobile-only consumers.”

For more information on the 2015 Mobile 500 or to order the guide, click here.

For information on a free webinar on the 2015 Internet Retailer Mobile 500, click here.

Follow Bill Siwicki, editor of the 2015 Internet Retailer Mobile 500 and managing editor, mobile commerce, at Internet Retailer, at @IRmcommerce.

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